Study on seasonal abundance and species diversity of butterfly fauna in Kiralakelle nature reserve: “A proposed site for ecotourism in Matara district.”

Abstract

Sri Lanka is one of the most biologically diverse countries in the world. Two hundred and forty four (244) species of butterflies have been recorded in Sri Lanka of which twenty one (21) are endemic. Nectar plants are one of the major determinant factors of life cycle, population abundance and distribution of butterflies. The present study investigated the seasonal abundance and diversity of butterflies in selected trails in Kiralakelle natural reserve, aiming promotional activity for an ecotourism site in Matara District. Four butterfly trails were selected during the initial survey and point scan line-transect technique was used to survey of butterflies. Abundance, Diversity and Evenness indices were estimated. Seasonal abundance of recorded butterflies was counted twice a month from January to December 2008. Active time period, occurrence and distribution of different vegetation strata and abundance of nectar plant of recorded butterflies were also studied during the survey. The recorded 24 butterflies represented 9 families and 24 species. Common Rose was the only recorded endemic butterfly. Banded Blue Pierrot and Small Banded Swift were recorded two rare species, Great Crow was uncommon, and threatened one was Banded Blue Pierrot. The highest number of butterfly species recorded in Family: Danaidae, Nymphalidae, PapiIionidae. Five butterfly species were abundant throughout the year. Seven butterfly species were found during the specific period from April to September/October. Species diversity was highest in trail 2, whereas species percentage was high in trail 1. Evenness was highest in trail 2 as it shown highest degree of spread of individuals between species. Traill had the highest abundance of butterflies with representing drastically high population of Blue Glassy Tiger. Great Crow represented only trail 1 and Angled castor confined to trail 2. Most suitable time period to watch butterflies is between 9.00 a.m. - 3.00 p. m. during the day and highest number of butterflies observed in ground level stratum( <lm). There was a significantly positive correlation (r2 = 0.816, P<0.05) between recorded overall abundance of butterflies and nectar plants in each trail. A check list of recorded butterfly species was prepared. In the light of overall result, trail I and 2 give high opportunity for tourists to enjoy by watching butterflies in Kiralakelle nature reserve. Additional conservation actions immediately require for trail 3 and 4, to minimize disturbance by human, buffaloes and solid waste. Furthermore, Butterfly populations could be enhanced by promoting the abundance of recorded food plants and forest shade in these disturbed habitats.